1. Field of the Invention
This invention concerns a process for producing a catalyst ingredient with uniform particle configuration for use in polymerization of olefins, particularly, .alpha.-olefins such as propylene.
2. Prior Art
Several attempts have been tried for the process of preparing solid catalyst ingredients comprising magnesium, titanium, halogen atoms and electron donating compounds as essential ingredients for use in polymerization of olefins, particularly, .alpha.-olefins having three or more carbon atoms, and they exhibit rather preferable catalyst performance with respect to the stereoregularity, catalytic activity and the bulk density of the obtained polymers.
For instance, a catalyst ingredient prepared by contacting a magnesium compound, an electron donating compound, a silicon compound having Si--H bonds and a titanium halide compound is proposed (Japanese Patent Laid-Open No. Sho 57-92009). However, the proposed magnesium compound is actually a magnesium halide compound, the silicon compound and titanium halide compound are simultaneously brought into contact upon use and their catalytic performance is not satisfactory.
The present inventors previously developed a catalyst ingredient prepared by contacting a magnesium alkoxide, a silicon compound having hydrogen-silicon bonds, an electron donating compound and a titanium compound capable of producing an olefin polymer having a high stereoregularity and high bulk density at high yield (U.S. Ser. No. 481,197, filed Apr. 1, 1983 and now abandoned), as well as a process for polymerizing olefins by using a catalyst in which the catalyst ingredient described above is combined with a specific cocatalyst system (U.S. Pat. No. 4,565,798). However, the catalyst ingredient developed by the present inventors was prepared by contacting the above-mentioned four ingredients substantially in the above-mentioned order, that is, contacting the magnesium alkoxide with the silicon compound having the hydrogen-silicon bonds, thereafter, contacting them with the electron donating compound and further with the titanium compound. It has been found that macro-polyolefin particles of greater than 1 mm diameter are formed in a rather great amount in a case where the olefin is polymerized by using the catalyst ingredient obtained in such a contacting method.